1. Field of the Invention
The present invention relates to a device and method for transporting a semiconductor wafer during processing, and more particularly, to a device and method having a plurality of angled surfaces for receiving, holding and transporting a semiconductor wafer during semiconductor processing.
2. Description of Related Art
During semiconductor manufacturing, the semiconductor wafer or substrate is typically moved to a processing module, or from one processing station to another. The wafer may be placed on a plurality of pad devices situated on a transfer arm. The pad devices assist in holding or supporting the wafer while being transported by the transfer arm.
Known pad devices typically have a wedge-shaped design whereby the pad devices are positioned on an end-effector, such as a transfer arm, used in semiconductor processing. The semiconductor wafer is then positioned on the pad devices and transported during processing.
A disadvantage of transferring wafers using current process flows and pad devices occurs when the receiving surface of the pad device touches the top or bottom surface area of the wafer, resulting in contamination thereof. As the wafer surfaces are developed during semiconductor processing, this contamination is undesirable as unwanted or residual particles remain on the wafer surfaces. Another disadvantage of current processing and pad devices is that when the wafer contacts a receiving surface of a pad device having a low rise, or relatively small angle from a respective horizontal plane, the receiving surface may also undesirably contact the bottom surface of the wafer resulting in contamination thereof. Additionally, other portions of the wafer, such as the edges, may be damaged using current processing and pad devices thereby causing difficulty when developing the semiconductor wafer.
Another undesirable aspect of known process flows and pad devices is that the wafer can shift on the pad device or transfer means while being transported. In so doing, the wafer slides and shifts on the pad device resulting in damage to the wafer, or further contact with, and contamination of, the bottom surface of the wafer. In shifting the wafer during transporting, physical damage may also occur to the wafer as a result of misalignment of the wafer causing surface of the wafer to undesirably contact unwanted objects. Such undesirable contact may render the wafer less desirable for processing or even result in discarding of the wafer, thereby reducing production yields. Misalignment of the wafer also may cause coatings or deposits of materials to be misapplied to the wafer, e.g., the film may be applied onto unwanted areas of the misaligned wafer and/or an undesirable film build-up can occur on the wafer, resulting in less productive surface areas of the wafer, or rejection thereof, leading to lower production yields.
Accordingly, a need exists in the art to provide improved process flows and transfer devices that neither contaminate nor damage the surfaces of a wafer during the process of both receiving and transporting the wafer, and doing so as rapidly as possible. Furthermore, as it is desirable to minimize the volume of the processing chamber, a need continues to exist in the art to provide improved pad devices having minimal vertical dimensions, thereby minimizing the required vertical clearance in the processing chamber.
Bearing in mind the problems and deficiencies of the prior art, it is therefore an object of the present invention to provide an improved support device and method for easily receiving and transporting a semiconductor wafer.
It is another object of the present invention to provide a support device and method which discourage movement of a semiconductor during transportation thereof.
It is yet another object of the present invention to provide a support device and method that discourage and reduce contamination of a wafer surface during transportation thereof.
It is a further object of the present invention to provide a support device having minimal vertical dimensions.
Another object of the invention is to provide a support device and method which more easily receives, holds, and transfers a semiconductor wafer.
It is a further object of the present invention to provide a support device and method for transferring a semiconductor wafer which minimize the vertical clearance needed in a processing chamber during placement of the wafer.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.